The present invention relates to an intermediate roller for driving carrying rollers of an accumulating roller conveyor. An accumulating roller conveyor is a conveyor that includes sectionally driven carrying rollers on which articles are transported. During their transportation, the articles act on a sensing element projecting in the conveyor path. The sensing element controls engagement or disengagement of the elements of a conveyor drive for changing the conveyor output in accordance with local conditions.
There exist accumulating roller conveyors which include an intermediate roller comprising a sprocket wheel, which engages a circulating chain. The driven wheel, which is drivingly connectable with the carrying roller, can be formed as a gear. This results in a twofold form-locking motion transmission. On one hand, such motion transmission advantageously insures a reliable and efficient transportation of articles but, on the other hand, it may cause a detrimental forcible slippage between the engaged drive elements if the conveying of articles is blocked.
The latter may result in the damage of conveyor parts and/or the articles, especially with a high power input. Further, during connection of the sprocket wheel with the driven wheel, difficulties exist in bringing the teeth of the two parts into engagement with each other, and a noticeable impact of teeth on each other can be observed.
German Patent No. 2,650,205 which discloses an accumulating roller conveyor, discloses a concept which insures a substantial insensitivity to disturbances during the starting period and, at the same time, provides for a high constant transmission of drive forces.
In German Patent No. 2,650,225, a combination of safety clutches and special toothing provides for a reliable overload protection during engagement and disengagement of form-locking parts with which drive force tansmission is effected.
German Patent No. 2,650,205 discloses an accumulating roller conveyor in which an intermediate roller, formed as a sprocket wheel, drives the article-carrying rollers and is displaced between its drive and free-running positions by a linkage which cooperates with a sensing element projecting in the conveyor path.
According to the German patent, the outer surface and the hub of the carrying roller, which is driven by the intermediate roller, form, in a per se known manner, a slide bearing, and the drive connection between the intermediate roller and the carrying roller is provided by flattened toothing.
In this accumulating roller conveyor, good results are achieved with regard to force transmission. However, with regard to the start, i.e., the time at which the carrying roller is set in rotation, start impacts can still be present.
Accordingly, an object of the invention is to provide an intermediate roller which would insure that the forces, generated at the beginning of driving of the conveyor, are dampened.